ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY INFORMATION - Financial Effect of the Modifications (Details)	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Commercial \| Commercial and industrial \| Term Extension
Financing Receivable, Modifications [Line Items]
Term Extension	11 months 1 day	1 year 4 months 2 days
Commercial \| Commercial and industrial \| Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Interest Rate Reduction	6.11%	4.00%
Commercial \| Commercial and industrial \| More-Than-Insignificant Payment Delay
Financing Receivable, Modifications [Line Items]
More-Than-Insignificant Payment Delay	0.26%	0.13%
Commercial \| Owner-occupied commercial \| Term Extension
Financing Receivable, Modifications [Line Items]
Term Extension	10 months 24 days	11 months 12 days
Commercial \| Owner-occupied commercial \| Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Interest Rate Reduction	0.00%	2.59%
Commercial \| Owner-occupied commercial \| More-Than-Insignificant Payment Delay
Financing Receivable, Modifications [Line Items]
More-Than-Insignificant Payment Delay	0.00%	0.00%
Commercial \| Commercial mortgages \| Term Extension
Financing Receivable, Modifications [Line Items]
Term Extension	5 months 23 days	1 year 3 months 29 days
Commercial \| Commercial mortgages \| Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Interest Rate Reduction	0.00%	0.00%
Commercial \| Commercial mortgages \| More-Than-Insignificant Payment Delay
Financing Receivable, Modifications [Line Items]
More-Than-Insignificant Payment Delay	0.00%	0.00%
Commercial \| Construction \| Term Extension
Financing Receivable, Modifications [Line Items]
Term Extension	1 year	1 year
Commercial \| Construction \| Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Interest Rate Reduction	0.52%	0.00%
Commercial \| Construction \| More-Than-Insignificant Payment Delay
Financing Receivable, Modifications [Line Items]
More-Than-Insignificant Payment Delay	0.15%	0.00%
Residential \| Term Extension
Financing Receivable, Modifications [Line Items]
Term Extension		20 years 2 months 4 days
Residential \| Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Interest Rate Reduction	4.25%	0.00%
Residential \| More-Than-Insignificant Payment Delay
Financing Receivable, Modifications [Line Items]
More-Than-Insignificant Payment Delay	0.00%	0.00%
Consumer \| Term Extension
Financing Receivable, Modifications [Line Items]
Term Extension	5 months 26 days	3 years 29 days
Consumer \| Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Interest Rate Reduction	0.00%	2.65%
Consumer \| More-Than-Insignificant Payment Delay
Financing Receivable, Modifications [Line Items]
More-Than-Insignificant Payment Delay	0.05%	0.06%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-34

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-33

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of decrease in weighted average contractual interest rate of financing receivable modified for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

+ Details

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted Average, More Than Insignificant Payment Delay For Modified Loans, Percentage

+ References

No definition available.

+ Details

Name:	wsfs_WeightedAverageMoreThanInsignificantPaymentDelayForModifiedLoansPercentage
Namespace Prefix:	wsfs_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wsfs_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_InterestRateBelowMarketReductionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PaymentDeferralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wsfs_OwnerOccupiedCommercialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wsfs_CommercialMortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: